EP3890922A1

EP3890922A1 - System and method for measuring the profile of a workpiece

Info

Publication number: EP3890922A1
Application number: EP19817418.7A
Authority: EP
Inventors: Philippe Jacot; Sébastien LAPORTE; Frédéric PERRET
Original assignee: LDI Finances SC
Current assignee: Watchoutcorp Sa
Priority date: 2018-12-04
Filing date: 2019-11-28
Publication date: 2021-10-13
Anticipated expiration: 2039-11-28
Also published as: TWI842790B; US20220028106A1; KR102671530B1; KR20210131993A; CN113260482A; US11854220B2; JP7220788B2; CN113260482B; EP3890922B1; JP2022510150A; TW202028692A; CA3157829A1; WO2020115621A1; CH715610A1; ES2972870T3

Abstract

The invention relates to a system and a method for measuring the profile of a workpiece. According to the invention, the measurement system (100) comprises: - a sensor (110) with a probe (120) having at least one degree of freedom, and a first reference element (130) secured to the probe (120), the sensor (110) being arranged such that the probe (120) is able to follow the inner or outer contour of the workpiece (50) while the first reference element (130) is outside the workpiece (50), and - an image capture device (160) capable of capturing an image representing at least a portion of the outside of the workpiece (50) and the first reference element (130). Thus, the first reference element (130) acts as a reference element for the position of the probe (120) relative to the reference frame which is the workpiece (50).

Description

System and method for measuring the profile of a part

Technical area

The present invention relates to the field of measuring the dimensions of an object or a part. In particular, the present invention relates to the field of determination by sensor (touch or non-touch) of the dimensions of an object or a part.

This type of measurement is used in many fields applying dimensional metrology, including in particular, but not exclusively, the field of machining parts, in particular by machine tool or any other machining by removing material, but also for manufacturing by adding material. This measure is particularly useful in the case of wear checks or during maintenance operations.

In the field of machine tools, there is a need to know precisely the dimensions and / or the profile of a part, in order to ensure a range of machining in accordance with the machining plan developed during the setting. on point.

State of the art

Different systems aimed at measuring the coordinates of an object in an opto-tactile manner have been proposed, in particular systems comprising a flexible probe. Document US2005259271 A uses a scanner in the form of a probe head mounted on a flexible probe extension. A first optical system forming a monobloc unit with the scanner detects the position of the probe head in an x, y plane while a second autonomous optical system detects the position of the probe head in the z direction.

Documents US2016370172A and US2005000102A show coordinate measuring systems comprising a probing head, the position of which is followed by an optical sensor mounted coaxially with the probe. In document US2016370172A, the probe is provided with a flexible extension with a contact element deviating from the contact with the workpiece and bearing a reference mark situated in the vertical alignment of the tactile part of the probe. In document US2005000102A, the coordinate measuring instrument comprises a probe head mounted on an extension and the position of which is identified by an optical system the optical axis of which is aligned with the probe head.

In these solutions, it is not possible or not always possible to measure the displacement of the probe head in the three directions of space, in particular if the probe head is hidden, in particular in a recess or a bore of the part.

Document US2009144999A describes a probe for measuring the interior contour of a hollow part. This probe comprises a bar, the lower end of which carries a probing head which comes into contact with the surface to be measured and the upper end of which emerges from the workpiece and carries a target whose position is identified by an optical sensor, in particular at laser. The bar is made mobile by mounting on a spherical articulation also offering a degree of freedom in

translation. This arrangement requires a support for the ball joint which is mounted on the part to be measured, which generates additional manipulation. In addition, calibration of the probe requires precise and reproducible mounting of the probe / support on the part to be measured.

The solutions of the prior art are dependent on measurements taken with respect to benchmarks external to the part and to the measurement system, namely that intermediate measurements with respect to axes of precision are involved in the measurement procedure. This adds steps in the measurement and leads to the accumulation of uncertainties, or even measurement errors, hence the provision of a final result concerning the measurement which is not as precise as desired.

These solutions therefore do not make it possible to have a device which is quick to set up and use, and above all which makes it possible to easily measure the profile, in particular the internal profile, of an object or a part, and especially a hollow part.

In addition, these solutions are not always of sufficient accuracy for certain applications.

Brief summary of the invention

An object of the present invention is to provide a measurement technology for performing a measurement of the profile, and in particular of the internal profile of an object or a part, free from the limitations of known measurement techniques.

Another object of the invention is to propose a technology making it possible to measure the profile, and in particular the internal profile of an object or a part, which provides a very precise measurement of the portions of a room.

Another object of the invention is to provide a technology for performing a measurement of the profile, and in particular of the internal profile of an object or a part, in a minimum of measurement steps.

According to the invention, these aims are achieved in particular by means of a system for measuring an external profile of a part or an internal profile of a hollow part, comprising:

- - a part whose internal or external profile is to be measured, - a sensor comprising a probe, and a first reference element secured to the probe, a base and a guidance system connecting the probe with the base allowing relative movement between them according to at least one degree of freedom defining a measurement direction ,

said sensor being arranged so that when the sensor moves relative to the workpiece in a direction different from the measurement direction, said probe is able to follow the internal or external contour of the workpiece while the first reference element is outside the part and performs a path reproducing the path of the probe (along the internal or external contour of the part, and

- a shooting device capable of taking images representing at least a portion of the outside of the part and the first reference element, whereby by comparison between the images taken by the shooting device, it is detected the relative displacement between the first reference element and the portion of the outside of the part in said measurement direction, and a relative displacement is deduced therefrom between the probe and the base which corresponds to a shift in the measurement direction along of the measured profile of the part.

This solution has the particular advantage over the prior art of not requiring direct identification of the position of the probe or of a probe head which would be in contact with the profile of the part since it is the first reference element, in any case remaining outside the part during the measurement, which is capable of reproducing the displacement of the probe and which serves as a reference element for determining the position of the point of contact between the face of the part and the probe. Thus, the first reference element serves as a reference element for the position of the probe relative to the reference frame which is the part itself.

This occurs in the first place when determining the external profile of a part or determining the internal profile of a hollow part, whether the hollow part is a through opening or not (through hole or blind hole). Also, secondly in the case of determining the internal profile of a part, thanks to the spatial offset between the probe and the first reference element, the probe can be left inside the part, in a hollow portion, while keeping the first reference element outside the part, which allows to keep the access (for example optically or by contact) to the first reference element and thus greatly facilitate the determination of the position of the probe via the determination of the position of the first reference element relative to the part.

The probe thus has at least one degree of freedom relative to the part, when the measurement system is stationary, in the position for measuring the profile of a part, and during the movement of the part with respect to the system. of measurement. This possibility of movement of the probe (or mobile part of the sensor) relative to the rest of the measurement system allows it to follow the contour (internal profile or external profile) of the part to be checked. It is understood that the shooting device has an optical field (or field of view) such that it makes it possible to see and therefore to take an image comprising both a portion of the outside of the room and the first element of reference. In this way, taking successive images during the movement of the part relative to the measurement system allows the shooting device to see by the movement of the first reference element in the field of view, what is the corresponding profile to this course of the first element of reference.

According to one arrangement, the internal contour or the external contour or both the internal contour and the external contour of the part forms a face of revolution about an axis. This axis is for example an axis parallel to the main axis of the sensor.

In one arrangement, the sensor further comprises a base and a guide system connecting the probe with the base. In this way, a controlled movement of the probe is obtained with respect to the rest of the measurement system when the latter is in a measurement position relative to a workpiece. According to a possible arrangement, said guide system allows a single degree of freedom between the probe and the base. Thus, there is a simple measurement system in its design and allowing the probe to follow the variation of the contour of the part in a direction authorized by the degree of freedom, which is suitable and is sufficient in a large number of cases. .

According to another arrangement, said measurement system further comprises a second reference element integral with the base and disposed outside the part, said second reference element being placed so that the shooting device is capable of simultaneously seeing said first reference element, said second reference element and said portion from the outside of the part. In fact, the second reference element remains in all cases outside the part whose internal or external profile is measured. This arrangement makes it possible to have, with the second reference element, a stationary element of the measurement system, serving as another fixed reference with respect to which the displacements of the first reference element can be viewed (via the shooting device) and consequently the movements of the probe, in particular in at least one direction authorized by the guidance system.

According to a first possibility of implementing the invention, the probe comprises a probing head capable of tracking and detecting the internal or external contour of the part by contact. Such a probe head physically follows the contour of the part to be measured, and in particular the internal contour, therefore hidden, during the measurement of the internal contour.

According to a second possibility of implementing the invention, the probe comprises a detection head capable of tracking and detecting the internal or external contour of the part without contact. For example, without limitation, it is a probe operating optically (optical detection head), or for example a proximity sensor (distance or proximity detection head) or even a sensor electromagnetic or acoustic (electromagnetic or acoustic detection head).

According to one arrangement, the shooting device comprises a camera and a light source capable of simultaneously illuminating said portion from the outside of the room and the first reference element. This arrangement makes it possible, in particular when the probe is placed in a hollow room and the first reference element is placed outside the room, to allow the camera to provide a sufficiently contrasted image.

According to one arrangement, the camera has a field of view making it possible to see said portion from the outside of the room and the first reference element. This arrangement makes it possible, in particular when the probe is placed in a hollow room and the first reference element is placed outside the room, to allow the camera to provide an image of the portion of the outside of the room and of the first reference element.

According to one arrangement, the guidance system comprises return means allowing the return of the movable part of the sensor, and therefore of the probe, in a rest position relative to the base when the probe is no longer in interaction with the internal or external contour of the part. Thus, during the interaction between the probe and the contour of the part, namely in particular the probing or contacting with support when the probe is a probing head, an effective interaction is guaranteed.

(in particular an effective contact) guaranteeing a position of the probe, therefore of the first reference element, corresponding to the contour of the part. If it is a contactless interaction, effective detection is guaranteed between the probe and the first reference element to allow measurement. In addition, when the measurement is made, these return means allow the movable part of the sensor, and therefore the probe, to return to a rest position, in which there is no stress.

(mechanical or otherwise) in the measurement system, in particular in the transmission chain (in particular kinematic chain) between the first reference element and the probe. These return means can take several forms, among which and without limitation, at least one or more of the following elements: deformable and elastic element, leaf spring (flat, curvilinear, spiral-shaped or other, etc.), spring helical,

. These return means can also arise from the structure of the guidance system which generates a natural return to this rest position due to simple gravity.

According to one arrangement, the guide system comprises between the probe (movable part of the sensor) and the base a sliding connection or else a tilting connection such as a pivot with mechanical elements, magnetic elements, hydraulic elements.

The invention also relates to a method for measuring the profile of a part, in particular with the system for measuring or determining the profile of a part as described in the present text. In particular,

the invention relates to a method of measuring the internal profile of a part using a measurement system as described in the present text. According to one possibility, the method for measuring a profile of a hollow part comprises the following steps:

i) supply of a sensor comprising a probe and a first reference element integral with the probe, a base and a guidance system connecting the probe with the base allowing relative movement between them according to at least one degree of freedom defining a direction of measurement ,, and of a shooting device,

ii) supply of a part whose profile is to be determined,

iii) placing the sensor so that the probe detects a point on the part's outline while the first reference element is outside the room and in the field of view of the camera, iv) triggering the system for taking a picture and forming an image representing at least a portion of the outside of the room and said reference element,

v) displacement of the sensor relative to the workpiece in a movement in a direction different from the measurement direction and allowing the probe stay inside the room and follow the outline of the room, while the first reference element stays outside the room by performing the same movement as the probe,

vi) carry out steps iv) and v) for other points of the contour of the part.

The invention also relates to a method of measuring the external profile of a part, in particular using a measurement system as described in the present text. According to one possibility, the method for measuring an external profile of a part, comprises the following steps:

i) supply of a sensor comprising a probe, a first reference element secured to the probe, a base and a guidance system connecting the probe with the base allowing relative movement between them according to at least one degree of freedom defining a direction measurement, and supply of a shooting device,

ii) supply of a part for which it is desired to determine the external profile, iii) positioning of the sensor so that the probe is outside the part and detects a point on the external profile of the part while the first reference element is also outside the room and in the field of view of the camera,

iv) triggering of the shooting system and formation of an image representing at least a portion of the outside of the room and said reference element,

v) displacement of the sensor relative to the workpiece in a movement in a direction different from the measurement direction and allowing the probe to follow the external contour of the workpiece, while the first reference element remains outside the workpiece performing the same movement as the probe,

vi) carry out steps iv) and v) for other points of the external contour of the part.

In general, the invention also relates to a method of measuring the profile, in particular internal or external, of a part. According to one possibility, such a method of measuring a profile of a part, comprising the following steps:

i) supply of a sensor comprising a probe, a first element of reference integral with the probe, a base and a guidance system connecting the probe with the base allowing relative movement between them according to at least one degree of freedom defining a direction of measurement, and provision of a shooting device,

ii) supply of a part whose profile is to be determined,

v) displacement of the sensor relative to the part according to a movement in a direction different from the direction of measurement and allowing the probe to follow the contour of the part, while the first reference element remains outside the part by performing the same movement as the probe,

vi) carry out steps iv) and v) for other points of the contour of the part.

According to an arrangement of one or other of these measurement methods, the following steps are also carried out:

a) for each image formed by said shooting device, calculation of the relative position between the first reference element and the portion of the outside of the part, and

b) reconstruction of the measured profile (internal or external) of the part from said relative positions of the first reference element successively calculated.

Brief description of the figures

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which:

FIG. 1 illustrates in perspective a first embodiment of the measurement system according to the present invention, FIG. 2 illustrates the partial sectional view in direction II of FIG. 1 of the measurement system according to the first embodiment of the present invention,

FIGS. 3 to 5 illustrate the different measurement steps from the front with the measurement system of FIG. 1,

FIG. 6 illustrates in section and from the front the principle of using the measurement system of FIG. 1 for measuring the internal profile of a part,

FIG. 7 illustrates in perspective and schematically the principle of a measurement method with the measurement system according to the first embodiment of the present invention of FIG. 1, in the case of the measurement of the internal profile of a room,

FIG. 8 illustrates from the front a variant of the first embodiment of the measurement system according to the present invention, FIG. 9 shows in a more schematic view from the front the variant of the first embodiment of the measurement system according to the present invention, illustrating the principle of the measurement carried out in the case of an internal part profile,

FIGS. 10A and 10B show steps of the measurement method with the variant according to FIG. 9 of the first embodiment of the measurement system according to the present invention,

FIGS. 11 and 12 schematically represent the general principle of the measurement system according to the present invention, FIGS. 13A and 13B illustrate the measurement steps with a second embodiment of the measurement system according to the present invention,

FIGS. 14A and 14B illustrate the measurement steps with a third embodiment of the measurement system according to the present invention,

FIGS. 15A and 15B illustrate the measurement steps with a fourth embodiment of the measurement system according to the present invention, FIGS. 16 and 17A to 17F respectively show the camera which can be used in the measurement system according to

the invention and the possible processing or analysis steps of the image taken by the shooting device during the implementation of the measurement method according to the present invention.

Example (s) of embodiment of the invention If we refer to FIG. 1, a measurement system 100 comprising a sensor 110 according to the present invention is shown in its rest position, without contact with a piece to measure. The sensor 110 comprises a base 112, here in the form of a prism in the shape of a rectangular parallelepiped, rigid and almost undeformable. The largest dimension of this base 112 defines the Y axis, or measurement axis. We distinguish on this base 112, along this axis Y, a first end 112a (on the right in FIGS. 1 to 7) and a second end 112b (on the left in FIGS. 1 to 7).

Plumb with the base 112, the sensor 110 comprises a support portion 114 having a shape and dimensions close to those of the base 112. This support portion 114 is also rigid and almost undeformable. There are on this support portion 114, along this axis Y, a first end 114a (on the right in FIGS. 1 to 7) and a second end 114b (on the left in FIGS. 1 to 7).

A deformable and elastic guide system 140 connects the base 112 and the support portion 114 of the sensor 110 along a Z axis or main axis of the sensor 110, this Z axis being vertical in the figures and when taking the measurement. . The base 112 and the support portion 114 are aligned with one another along the axis Z in the rest position of the sensor 110.

In alignment with the main axis Z of the sensor 110, the support portion 114 is extended, from its side turned opposite to the base 112, by a feeler rod 122 and by a rod of a first reference element 131, also parts of the sensor 110. This feeler rod 122 and this rod of a first reference element 131 are mounted by one of their free ends on the support portion 114. In the rest position the feeler rod 122 and the stem of a first reference element 131 are parallel to each other and to the main axis Z. The feeler rod 122 and the stem of a first reference element 131 are distant (and equidistant) from each other along the measurement axis Y of a distance Y0 (see Figure 6). Thus, the feeler rod 122 and the rod of a first reference element 131 define a plane (Y, Z).

Thus, in the rest position of the sensor 110, the direction orthogonal to the probing rods 122 and the first reference element 131 and which passes through these two rods 122 and 131 is the measurement axis Y. We define a transverse axis X which is orthogonal to the plane (Z, Y) and which is orthogonal to the feeler rod 122 and to the rod of the first reference element 131. The axes X, Y and Z define an orthogonal coordinate system, preferably orthonormal. These rods 122 and 131 are for example metal rods, in particular steel.

The free end (lower end in Figures 1 and 2 to 8) of the feeler rod 122 ends with a feeler head 123 forming a probe head 120 for the sensor 110 of the measurement system 100. This probe head 123 is for example of metal, and in particular in the same metal or metallic alloy as the probe rod 122. The probe head 123 is for example ( see Figure 6) formed of a sphere with the axis of the feeler rod 21 passing through the center of the sphere. In an alternative embodiment visible in FIGS. 1, 3 to 5 and 7, the probe head 123 is formed by a portion of a sphere, in this case a half-sphere, mounted on the side of the free end of the probe rod 122, which is turned in the direction of the rod of the first reference element 131: in other words, the axis of the hemisphere (probe head 123) is oriented along the Y axis. In all cases, the probe head 123 has a portion which projects from the probe rod 122, in the direction Y, and in the direction of the rod of the first reference element 131. That is to say that there is a portion of the feeler head 123 which protrudes beyond the feeler rod 122 along the Y axis, this protruding portion of the feeler head 123 being turned towards the reference rod 24 (reference head 25 ). In this way, as will be seen below, the feeler head 123 can be brought into contact with a surface of a workpiece without the feeler rod 122 also being in contact with the surface of the workpiece.

The free end (lower end in FIGS. 1 and 3 to 8) of the rod of the first reference element 131 ends with a first reference element 130. This first reference element 130 is for example made of metal, and in particular in the same metal or alloy

metallic than the rod of the first reference element 131. The first reference element 130 is for example (see FIGS. 1 to 7) formed of a sphere with the axis of the rod of the first reference element 131 passing through the center of the sphere.

Thus, in the embodiment shown in Figures 1 to 8, the probe head 123 is mounted at the free end of the probe rod 122 and the first reference member 130 is mounted at the free end of the rod of the first reference element 131. Also, in the embodiment shown in FIGS. 1 to 8, the feeler rod 122 and the rod of the first reference element 131 are of the same length, or more exactly protrude from the support portion 114 by the same length along the axis Z. In this way, the probe head 123 and the first reference element 130 are distant from the support portion 114 by the same distance Z0 ( see figure 6). In other words, the probe head 123 and the first reference element 130 are below and at the same distance from the support portion 114.

To allow the displacement along the Y axis of the probe head 123 to be transferred to the first reference element 130, the guide system 140 which connects the support portion 114 to the base 112 is

deformable and elastic at least along the Y axis. Different modes of implementation are possible: among which one or more elastic elements mounted between the support portion 114 and the base 112. In the case of the embodiments illustrated in the figures 1 to 8, two leaf springs 141, 142 are used as guide system 140. These two leaf springs 141, 142 are identical and, in the rest position of the sensor 110, parallel to each other, to the main axis Z and to the transverse axis X. In other words, the plane of the leaf springs 141, 142 at rest is parallel to the plane X, Z, therefore the plane of the leaf springs 141, 142 at rest is orthogonal to the axis Y as can be seen in FIG. 1, a first spring leaf 141 is mounted between the first end 112a of the base 112 and the first end 114a of the support portion 114. A second spring leaf 142 is mounted between the second end 112b of the base 112 and the second end 114b of the support portion 114. Alternatively, one could use four leaf springs parallel to each other and to the axes Z and X, and mounted in pairs, a pair of leaf spring mounted between the first end 112a of the base 112 and the first end 114a of the support portion 114 and another pair of spring blades mounted between the second end 112b of the base 112 and the second end 114b of the support portion 114.

With this arrangement, in the rest position of the sensor 110 (rest position of the measurement system 100), a frame is formed with the base 112, the support portion 114 and the two leaf springs 141 and 142. This frame forms a rectangle in the plane (Y, Z) in the rest position of the sensor 110, with the length of the rectangle parallel to the Z axis and the width of the rectangle parallel to the Y axis. With this arrangement, in the measurement position of the sensor 110, we can deform this rectangle as we can see on Figure 5. In this situation, the base 112 and the support portion 114 remain parallel to each other and to the Y axis, with an offset dY1 along the Y axis of the support portion 114 and the rods (heads) of the first reference element 131 (130) and the second reference element 151 (150), and the leaf springs 141 and 142 are deformed. In this measurement position, the deformed profile of the spring blades 141 and 142 comprises in the plane (X, Z) two substantially rectilinear end parts and a central part forming a curve with an inflection point.

Thus, the movable part of the sensor 110 forms a probe 120 comprising the support portion 114 and the elements which are attached to it: the probe rod 122, the probe head 123, the first reference element (rod 130 and head 131) and the guide system 140 (leaf springs 141 and 142). When we return from the measurement position to the rest position, namely that the probe head 123 is no longer in contact with the face of the part, the leaf springs 141 and 142 return to their initial rectilinear shape and the portion of support 114 returns to the vertical of base 112.

According to the embodiment shown in Figures 1 to 5 and 8, the guide system 140 further comprises a bar 143 whose first end 143a (upper end in the figures) is fixed integrally to the base 112 and the second end of which 143b

(lower end in the figures) is mounted on the support portion 114 by a sliding connection at least in the direction Y. In this embodiment, the connection between the second end 143b of the bar 140c is the support portion 114 is also sliding in direction Z, which makes it possible to absorb the deformation of the spring blades 141, 142 or more generally of the guide system 140 in direction Z.

In practice, in the arrangement shown in Figures 1 to 5 and 8, the support portion 114 has a groove 114c opposite the base 112, open on the upper face of the support portion 114.

As can be seen in FIG. 2, the groove 114c has a sufficient width I0 along the axis X to accommodate without clearance the free end or second end 143a of the bar 143. As can be seen in FIG. 2, the groove 114c has a length L0 along the axis Y to accommodate and allow the displacement of the free end or second end 143b of the bar 143 towards the first end 114a or the second end 114b of the support portion 114 according to a maximum distance pre - established corresponding to the maximum admissible for the offset dY1 (dY1 max). Thus, if the bar 143 has a cylinder shape with a circular section of diameter D, the groove 114c has a width I0 equal to or substantially greater than D (I0 is between D and 1.05D), and a length L0 equal to D + 2 (dY1 max). This groove 114c is therefore generally elongated along the axis Y. By way of example, this groove 114c can be rectangular, oval or oblong (buttonhole). This groove 114c is through or not through (blind groove) on the underside of the support portion 114. By way of example, the maximum admissible for the offset dY1 (dY1 max) is a few milllimeters, for example 2, 5, 7 or 10 millimeters, right and left in Figures 2 to 5.

Referring to FIGS. 3 to 5, showing the sensor 110 in the case of the measurement of the external profile of a part 50, therefore of a face 51 of the part forming an external face 51. Preferably, this part 50 is a part of revolution around the axis Z, for the face to be measured, namely for the external face 51 (and possibly also for the internal face 54.

More generally, such a method for measuring the external profile of a part comprises the following steps:

a) a sensor 110 is provided as described in the present text,

b) a part 50 is provided, the external profile of which is to be determined, namely the measurement of the profile of the face 51 (external face),

c) a shooting device 160 is provided (external sensor as in FIG. 7) capable of determining the position of the first reference element 130, (here, as seen in FIG. 3, the sensor 110 is in position rest, with the support portion 114 and the base 112 in the initial position, aligned one above the other along the Z axis)

d) the probe head 123 is placed against the external face 51, while the first reference element 130 remains at a distance, that is to say at

outside) of said part 50 (movement according to arrow F1 in FIG. 3, by bringing the sensor 110 and the external face 51 of the part 50, along the axis Y, to arrive at the intermediate position of FIG. 4 in which the guide system 140 is not deformed)

e) the sensor 110 is moved so that the probe head 123 remains in contact with the external face 51 of the part, with the base 112 which moves relative to the support portion 114 and relative to the part 50 according to the Y axis (relative movement between the probe 120 and the basel 12), (movement according to the arrow F1 in FIG. 4, with the base 112 of the sensor 110 which moves relative to the part 50 along the Y axis d 'a distance dY1, to arrive at the measurement position of the sensor 110), and

f) the position of the first reference element 130 is identified by said shooting device 160, which makes it possible to determine the position of the probe head 123 on the face 51 of the part 50, and

g) the sensor 110 is moved so that the probing head 123 of the probe 120 comes to another location on the external face 51 of the part 50 while keeping contact between the probing head 123 and the external face 51 of the part 50 (in FIG. 5, vertical displacement along the Z axis along arrow F2, but this can be a displacement along the X direction and / or the Y direction depending on the geometry of the part 50), then the steps are reproduced f) and g) until the end of the determination of the external profile (or of the portion of the external profile) of the part 50.

In the case of a hollow part 50 (bore, recess, hole, light, housing 52), the procedure is similar, placing the probe head 123 of the probe 120 inside the part 50 (in the housing 52), against the internal face 54 of the part 50 while the first reference element 130 remains outside of the part 50, as explained in relation to FIGS. 6 and 7. In FIG. 6, the part 50 comprises a through hole 52 as housing and in FIG. 7, the part comprises a blind hole 52 as housing. Preferably, this part 50 is a part of revolution around the axis Z, for the face to measure, namely for the internal face 54 (and possibly also for the external face 51).

In this case, such a method of measuring the internal profile of a part 50 comprises the following steps (see FIGS. 6 and 7):

a) providing a sensor 110,

b) a hollow part 50 is provided, the internal profile of which is to be determined (internal face 54 of the housing 52),

c) a shooting device 160 is provided (external sensor as in FIG. 7) capable of determining the position of the first reference element 130,

d) the probing head 123 is placed inside said hollow part 50, with the probing head 123 against the internal face 54, while the first reference element 130 remains outside said hollow part 50 ( here, as can be seen in FIG. 6, the sensor 110 is in the rest position, with the probe 120, and in particular the support portion 114 and the base 112, in the initial position, the support portion 114 and the base 112 aligned one above the other along the Z axis),

e) the sensor 110 is moved so that the probe head 123 enters (or remains) in contact with the internal face 54 of the part 50, and

f) the new position of the first reference element 130 is identified by said shooting device 160, which makes it possible to determine the new position of the probe head 123 in the part 50, and

g) the sensor 110 is moved to another location on the internal face 54 of the part 50 while keeping the contact between the probe head 123 and the internal face 54 of the part 50, then steps f) and g) are repeated until the end of the determination of the internal profile of the part 50.

The shooting device 160 (external sensor) is used to locate and determine the position of the first reference element 130 and the variation of its position, each time that the sensor 110 is moved relative to the face 51 or 54 of the part 50 to be measured, therefore that the probe head 123 has moved on the face to be measured 51 or 54. Indeed, in the case of FIG. 7, if the new position of the first reference element 130 strictly corresponds to a displacement along Z conforming to that of sensor 110 then the new position of the probe head 123 therefore the new measured point of the internal profile of the part 50 remains in the same position in Y as previously (dY = 0). In another case, not shown, in which the face 54 to be measured is not parallel to the vertical direction Z, but corresponds for example to a truncated cone of axis Z, then after displacement along the vertical axis Z of the sensor 110, the new position of the first reference element 130 corresponds not only to a displacement along Z in accordance with that of the sensor 110 but also to a displacement along Y then the new position of the probe head 123 therefore the new measured point of the internal profile of the part 50 comes to a new position in Y relative to the previous position of the sensor (dY is not 0). To this end, the shooting device 160 comprises an optical sensor. In this case, we can take a shooting device 160 whose optical axis O is arranged orthogonal to the plane (Y, Z) (see FIG. 7), in order to be able to detect the displacements of the first element reference 130 (and therefore indirectly from the probe head 123) along the Y axis.

Such a shooting device 160 is for example formed by an optical system, in particular a centered optical system, comprising a set of optical components and an image acquisition system. Such an image acquisition system makes it possible to take photographs and / or videos, and is for example a camera or a device

photographic, including a digital camera.

The shooting device 160 has intrinsic properties allowing it to have a field of view 162 which covers the first reference element 130 located outside of the part 50. We can see in Figure 6 the projection in the plane (Y, Z) of the field of view 162 or solid angle through which the camera 160 is sensitive to electromagnetic radiation (light). In the case shown in FIG. 6, the field of view 162 of the shooting device 160 comprises the first reference element 130, and it also covers or includes the part 50 or at least the portion of the part 50 comprising the face to be measured 54 (internal face 54), in particular the portion of the external face located in the plane (Y, Z) of the field of view 162 and corresponding to the face to be measured (if it is the external face 51) or opposite the face to be measured 54 (if it is the internal face 54).

According to a variant of the first embodiment illustrated in FIG. 8, the sensor 110 'further comprises a second reference element 150 mounted integrally with the base 112 and located near the first reference element 130, and in all cases outside of the part 50 (at the front and above the first reference element 130 in the arrangement of FIG. 8). More specifically, the rod of the second reference element 151 is fixed to the side of the base 112 forming the first end 112a of the base and which is located directly above the first end of the support portion 114 and the first element Reference 130. Also, the shape and the length of the rod of the second reference element 151 which rigidly connects the base 112 to the second reference element 150, are arranged to avoid any contact and any collision between the first reference element 130 and the second reference element 150. In this embodiment, the second reference element 150 is a sphere of size similar to the sphere constituting the first reference element 130. In the present text, the sensor bearing the reference 110 ′ therefore corresponds in the case of the presence of a second reference element 150 cooperating with the first reference element 130 to allow the measurement to be made. Indeed, it is understood that the second reference element 150 being integral with the base 112, it is fixed relative to this base 112, while the probe 120 and in particular the first reference element 13 is movable relative to the base 112.

With this second reference element 150, it is possible to detect the offset along the Y axis of the feeler head 123, said offset (not shown) being due to the bending of the feeler rod 122 during the support of the feeler head 123 against a face to be measured 51 or 54. In this case, in the previously described measurement methods, a second reference element 150 is also provided, mounted integrally with the base 112 and located near the first reference element 130, and in which during step f) of measurement, it further detects the

relative displacement (in particular along the Y axis) between the first reference element 130 and the second reference element 150, and this relative displacement is taken into account in determining the position of the probe head 123. It is therefore understood that the field of view 162 of the shooting device 160 also includes the second reference element 150.

Such a second reference element 150 is also useful also for measuring the external profile because the same phenomenon of bending along the Y axis of the feeler rod 122 is likely to occur, and this always without the existence any bending of the rod of the first reference element 131 since the first reference element 130 is not in contact with a surface, therefore is not subjected to a support which could generate a restoring force on the part of the surface and therefore a bending deformation of the rod of the first reference element 131.

In the case of this variant of the first embodiment, the method for measuring the internal profile of a part 50 comprises the following steps (see FIGS. 9, 10A and 10B):

a) a sensor 110 ′ is provided as described above,

c) a shooting device 160 is provided (external sensor as in FIG. 9) capable of determining the relative position between the first reference element 130 and the second reference element 150,

d) the probe head 123 is placed inside said hollow part 50, with the probe head 123 against the internal face 54, while the first reference element 130 and the second reference element 150 remain at the outside of said hollow part 50 (here, as seen in FIG. 10A, the sensor 110 ′ is in the rest position, with the support portion 114 and the base 112 in the initial position, aligned one above the other along the Z axis, as well as the first reference element 130 and the second reference element 150 aligned one above the other along the Z axis on a reference line R), e) the sensor 110 ′ is moved relative to the part 50 along the axis Y (arrow F1, FIG. 10B) so that the probe head 123 enters (or remains) in contact with the internal face 54 of the part 50 : this generates a pressing force (arrow A) of the first reference element 130 against the internal face 54 and the deformation of the spring blades 141 and 142 with an opposite displacement and of the same intensity (arrow F3) of the support portion 114 relative to the base 112, this generates an offset dY1 in the Y direction of the first reference element 130 relative to the second reference element 150 (FIG. 10B with offset in the Y direction, in the direction of the arrow F3 of the entire probe 120), and

f) the position of the first reference element 130 relative to the second reference element 150 is identified by said shooting device 160, which makes it possible to determine the position of the probe head 123 in the part 50, and

g) the sensor 110 ′ is moved in the Z direction (vertical direction) to another location on the internal face 54 of the part 50, keeping the contact between the probe head 123 and the internal face 54 of the part 50, then reproduces steps f) and g) until the end of the determination of the internal profile of the part 50. In this way, as seen in FIG. 9, we build point to point as successive positions taken by the first reference element 130, a measurement line M representing the internal contour of the internal face 54. It is understood that one uses as reference the vertical reference line R passing through the second reference element 150 (for example by its center or another point), and that the measurement line M is a transposition outside of the part 50 of the line C (FIG. 9) of the internal contour (internal profile) to be measured.

In this first embodiment, the sensor 110 or 110 'forms, with the base 112 forming the fixed reference in the sensor, a parallel deformation structure comprising one above the other in parallel with the base 112 and the support portion 114 which are each non-deformable, and the two spring blades 141 and 142 deformable in the horizontal direction Y. This makes it possible to define a measurement axis, here the Y axis and makes it possible to apply a force of support of the probe head 123 on the part 50. This bearing force depends on the characteristics of the spring blades 141 and 142 (length, width, thickness) and on their deformation.

In this first embodiment, but also generally, the invention allows, as seen in Figure 11, to follow very precisely the internal (or external) contour of the part 50 along the face internal 54 (external 51), by the probing head 123 of the probe 120 which remains in contact with the part 50. In the embodiments presented, the reconstruction and monitoring of the contour takes place in the vertical direction Z (orientation of the measurement line M and the contour line C to

reconstitute), but it is possible to envisage carrying out this reconstitution and this monitoring of the contour in another direction, in particular a horizontal direction, for example in the direction X, or another direction in the plane (X, Y), or even according to the first one of these previous directions for a portion of contour then in a second of these preceding directions to change the portion of contour and return to the first of these previous directions to view this new portion of contour. Despite the fact that this probe head 123 is invisible from the outside of the part 50, and this due to its position inside the housing 52, the invention makes it possible to visualize its displacement on the face to be measured 54, and this via the first reference element 130. The guide system 140 allows movement of the probe head 123 relative to the base 112 in one or more directions.

The invention allows via the shooting device 160 which is arranged with a field of view 162 including the first reference element 130 and the outer contour of the part and / or the second reference element 150, to take successive images during the displacement of the first reference element 130 and of measuring its relative position relative to the external contour of the part 50 (and possibly relative to the second reference element 150). These images make it possible to form the measurement line M point to point, which reconstitutes the line C of the internal contour to be measured. This is made possible because the measurement system transfers the displacement of the probe head 123 when it follows the internal (or external) contour of the part 50, and therefore the internal profile (or external) of the part 50, to the first reference element 130 which is outside the part. The measurement line M in FIG. 9 corresponds to the internal profile of the part 50 along the vertical direction Z at a location (a point) of the part (of the housing 52) in a horizontal plane parallel to the plane (X, Y ). To reconstruct the entire internal (external) profile of the part 50, namely the entire surface of the internal face

(external) 54 (52), the measurement steps must be repeated to reconstitute another measurement line M 'passing through another location (a point) of the part (of the housing 52) in this horizontal plane parallel to the plane (X ,

Y), and so on for the number of points required. The reconstruction of the measurement line M amounts to reproducing outside of the part 50 the outline of a "slice" of the part 50 in a plane parallel to the vertical axis Z and orthogonal to the plane (X, Y). By also reconstructing other slices, each slice of the contour of the part 20 being located in another plane parallel to the vertical axis Z and orthogonal to the plane (X, Y), offset by a theta angle from the plane of the slice previously reconstituted, the juxtaposition of the measurement lines M, M 'etc. is obtained by adding images in a three-dimensional space. This is all the more rapid in the case of a part 50 of revolution which can be reconstituted in a few slices.

A preliminary preliminary calibration step is carried out in order to exactly determine the relative position between the first reference element 130 and the position of the probe head 123, which then makes it possible to transfer the measurement line M to obtain the line C of the internal contour which one seeks to measure and which is invisible from the outside of the room. To this end, according to one possibility, an image is taken of the sensor 110 or 110 ′ with the shooting device 160, without the part 50, in order to define the relative position of the first reference element 130 and to the probe head 123 in the rest position of the sensor 110 or 110 '.

The sensor 110 or 110 'can be held by its base 112 by a gripping member or a support member (shown schematically in Figure 12) and moved by any displacement system such as an articulated arm controlled by control systems and motorized shafts 170 in order to allow relative movement between the sensor 110 or 110 'and the part 50 according to:

- a horizontal movement along the Y axis according to the arrow F1 in FIG. 12, and / or

- a vertical movement along the Z axis according to arrow F2 in FIG. 12.

Referring now to Figures 13A and 13B showing a measurement system 200 according to a second embodiment of the invention. In this case, the elements of the measurement system 200 similar to those of the first embodiment presented above (measurement system 100) bear a reference sign which is that of the first embodiment increased by a value of 100. We find a sensor 210 comprising:

a support portion 214 extended vertically downwards by a feeler rod 222 carrying at its free end a feeler head 223 and in parallel a rod of first reference element 231 carrying at its free end the first reference element 230 ,

a base 232 extended vertically downwards from a rod 251 of a second reference element carrying at its free end a second reference element 250. A variant not shown may not include this second reference element 250 but only the base 232 .

The support portion 214 and the base 212 are placed one in front of the other (in the horizontal direction X) with a guide system 240 allowing a rotational movement between them around an axis P parallel to the horizontal direction X. This direction X is

orthogonal to the horizontal measurement direction Y separating between them the feeler head 223 and the first reference element 230. For this purpose, the guide system 240 connecting the support portion 214 and the base 212 can take several designs, and in particular comprise a shaft (not shown) parallel to the axis P and disposed vertically (the vertical in FIGS. 13A and 13B, ie in the direction Z) of the probe head 223. This shaft passes through the support portion 214 and the base 212, and is mounted fixed relative to one of the two among the support portion 214 and the base 212 and is mounted movable relative to the other of the two among the support portion 214 and the base 212, which constitutes a bearing. The guide system 240 also optionally comprises a spiral spring (not shown) of axis parallel to the axis P (possibly coaxial with the axis P) surrounding said shaft with its inner end fixed on the shaft and its outer end fixed to the other of the two from the support portion 214 and the base 212. This movement of rotation of the guide system 240 around the axis P (see arrow F3 in FIGS. 13A and 13B) is facilitated by the presence a counterweight 241 connected to the outside of the support portion 214, with an offset in the direction Y between the support portion 214 and the counterweight 241. Thus, this counterweight 241 serves as a counterweight to the assembly formed of the probing head 223 and of the first reference element 230. The mass of this counterweight 241 can be modified as well as the distance L1 which separates it from the shaft (from the axis P), and therefore from the probing head 223, and so as to form an adjustable lever arm.

In this case, the probe 220 (probing head 223 at the free end of the probing rod 222) is connected to the fixed part of the measurement system by a guide system 240 allowing only rotation relative to an axis P orthogonal to the direction Y of the measurement. It is therefore in this case a pivoting guide system 240. Other designs are of course possible for this pivoting guide system between the probe 220 and the fixed part of the sensor 210 (for example the base 212), forming a guide system 240 allowing a rotational movement between them around a axis P parallel to the horizontal direction X.

A pendulum type structure is thus formed which works in the same way as the sensor 110 ′ according to the variant of the first embodiment and makes it possible to define a measurement axis, in the direction Y. This structure ensures a constant and extremely low bearing force A of the feeler head 223 on the internal face 54 (or external 51) of the part, regardless of the deformation of the spiral spring. In this case, the guidance system 240 authorizes a degree of freedom of the probe 220 which is a rotational movement around the axis P, parallel to the X axis. The return to the rest position of the probe 220 (in particular of the support portion 214 and of the elements which are attached to it) is effected by simple gravity once the probing head 223 has is no longer in contact with one face of the part 50. The use of this sensor 210 in combination with a shooting device 160 makes it possible to constitute a system for measuring the profile of the part according to a measurement method identical to that already described in connection with the first embodiment.

Such an arrangement forms a measurement system 200 in which:

the part 50 is hollow and the internal contour of the part 50 forms a face 54 of revolution around an axis of revolution (this axis of revolution is for example parallel to the main axis of the sensor 110, for example according to the Z axis),

the probe 220 comprises a probing head 223 capable of detecting by contact the internal contour of the part 50 and of following the internal contour of the part 50 with a degree of freedom in a measurement direction (direction Y) perpendicular to said axis of revolution, this measurement direction

(direction Y) separating between them the probe head 223 and the first reference element 230,

- The guidance system 240 includes a tilting link between the probe 220 and the base 212 around an axis (P) perpendicular to said axis of revolution and orthogonal to the measurement direction (direction Y).

It is understood that this measurement system 200 further comprises a second reference element 250 integral with the base 212 and located outside the room, the shooting device 160 being able to take an image further comprising the second reference element 250, whereby the variation of the relative position between the first reference element 230 and the second reference element 250 enables the profile of the internal contour of the part 50 to be measured.

An arrangement such as that according to FIGS. 13A and 13B allows the implementation of a measurement method as previously described, in which the following steps are also carried out: the images taken by the shooting device 160 are compared in order to detect the relative displacement between the first reference element 130 and the portion of the outside of the part 50 in said measurement direction, and

- a relative displacement is deduced therefrom between the probe 120 and the base 112 which corresponds to an offset in the direction of measurement along the measured profile of the part 50.

In particular, when the part 50 is hollow and the internal contour of the part 50 forms a face 54 of revolution around an axis of revolution (in particular an axis of revolution parallel to said main axis Z of the sensor 110),

the probe 220 comprises a probing head 223 capable of detecting by contact the internal contour of the part 50 and of following the internal contour of the part 50 with a degree of freedom in a direction Y of measurement

perpendicular to said axis of revolution (in particular a direction Y of measurement perpendicular to the main axis Z of the sensor 110), this direction Y of measurement separating between them the probe head 223 and the first reference element 230,

the guidance system 240 comprises a tilting link between the probe 220 and the base 212 around an axis P perpendicular to said axis of

revolution and orthogonal to the Y direction of measurement.

in the mode of implementation illustrated in FIGS. 13A and 13B, the sensor 210 further comprises a second reference element 250 integral with the base 212 and located outside of the part 50, the shooting device 160 being able to take an image further comprising the second reference element 250, whereby the variation of the relative position between the first reference element 230 and the second reference element 250 allows the measurement of the profile of the internal contour of the part 50.

Referring now to Figures 14A and 14B showing a measurement system 300 according to a third embodiment of

the invention. In this case, the elements of the measurement system 300 similar to those of the first embodiment presented previously carry a reference sign which is that of the first augmented embodiment. with a value of 200. There is a sensor 310 comprising:

a support portion 314 extended vertically downwards by a feeler rod 322 carrying at its free end a feeler head 323 and in parallel by a rod of first reference element 331 carrying at its free end the first reference element 330, this support portion 314 has a general shape of L with the stem of the L oriented in the vertical direction Z and the base of the L parallel to the direction Y and carrying the probe head 323 and the first reference element 330,

a base 312 extended vertically downwards from a rod 351 of a second reference element carrying at its free end a second reference element 350. A variant not shown may not include this second reference element 350 but only the base 312 .

The support portion 314 and the base 312 are movable relative to each other in the direction of the horizontal measurement axis Y, in a translational movement. Here, the base 312 has a stirrup shape, in particular an inverted U shape, with the base of the U parallel to the direction Y and the two branches of the U parallel to the direction Z. One of the two branches of the U of the base 312 is extended by the rod 351 of the second reference element and by the second reference element 350. Two guide pieces parallel to each other and to the direction Y connect the two branches of the U to each other for allow the translational movement of the support portion 314. More specifically, a rail 344 forms the first guide part in the form of a rod which has

preferably a circular section and on which is mounted the support portion 314 at a through opening in the portion of the rod of the L. Also, a slide 345 forms the second guide piece in the form of a rod parallel to the rail 344. To cooperate in translation with the slide 345, this other portion of the rod of the L has for example a notch to partially surround the slide 345 or else a through opening forming a passage for the slide 345.

In order to exert a pressing force (arrow A) by the probing head 323 on the internal (or external) face 54 (51) of the part which is for example oriented in the vertical direction and allow the return to the rest position (FIG. 14A) of the support portion 314 relative to the base along the Y axis, two compression springs 346 and 347 are used forming return means of the support portion 314. These springs 346 and 348 are mounted on the rail on either side of the support portion 314. These springs 346 and 347 have one end in contact and bearing on the support portion 314 ( a spring for each face) and one end in contact and bearing on the base 312 (each spring bearing on a branch different from the U of the base 312). These are, for example, as in the example shown in FIGS. 14A and 14B, two helical springs

346 and 347. In the example shown in FIGS. 14A and 14B, these are two springs 346 and 347 of the same length and of the same compressive strength per unit of length, which places the rest position (see FIG. 14A) of the support portion 314 between the two arms (ends in the measuring direction Y) of the base 312. However, the geometrical and / or physical characteristics of each spring 346 can be adapted and

347 according to specific needs. It is understood that in this arrangement, the pressing force A of the probe head 323 on the part 50 depends on the deformation of the springs 346 and 347: thus in the case of FIG. 14B, the probe head 323 presses on the internal face 54 of the part 50, in the zone on the right in the figure on a portion of internal face 54 vertical, as seen by the camera; in this case, the sensor 310 has been shifted in translation to the right relative to the part 50, which has displaced the support portion 314 relative to the base 312 to the left by the distance dY1 (see FIG. 14B) and put in compression (more) the first spring 346 located to the left of the support portion 314. We find this offset dY1 between the first reference element 330 secured to the support portion 314 and the second reference element 350 secured to the base 312.

Referring now to Figures 15A and 15B showing a measurement system 400 according to a fourth embodiment of the invention. In this case, the elements of the measurement system 400 similar to those of the measurement system 300 according to the third embodiment presented above carry a reference sign which is that of third embodiment increased by a value of 100. There is a sensor 410 comprising:

a support portion 414 extended vertically downwards by a feeler rod 422 carrying at its free end a feeler head 423 and in parallel by a rod of first reference element 431 carrying at its free end the first reference element 430, this support portion 414 has a general shape of a lying U with the base of the U oriented in the vertical direction Z, the upper branch of the U oriented in the direction Y and the lower branch of the U (carrying the probing head 423 and the first reference element 430) oriented also parallel to the direction Y,

a base 412 extended vertically downwards from a rod 451 of a second reference element carrying at its free end a second reference element 450. A variant not shown may not include this second reference element 450 but only the base 412 .

The support portion 414 and the base 412 are movable relative to each other in the direction of the measurement axis which is this time the vertical axis Z, in a translational movement. Here, the base 412 also has a stirrup shape, in particular a shape of a lying U, with the base of the U parallel to the vertical Z and the two branches of the U parallel to the direction of the Y axis; the opening of the U of the support portion 414 is turned towards the base 412; the opening of the U of the base 412 is turned in the direction of the support portion 414; One of the two branches of the U of the base 412 (lower branch) is extended by the rod 451 of the second reference element and by the second reference element 450, and is partially disposed in the housing delimited by the support portion 414, while at least in projection in the plane of FIG. 15A or 15B, that is to say seen in direction X by the shooting device 160 (not shown). Two guide pieces parallel to each other and to the direction Z connect to one another the two branches of the U of the base 412 to allow the translational movement of the support portion 414. More specifically, a rail 444 forms the first guide piece in the form of a rod which preferably has a cross section circular and on which is mounted the support portion 414 at a through opening in the portion of the other of the two branches of the U of the base 412 (upper branch). Also, a slide 445 forms the second guide piece in the form of a rod parallel to the rail 444. To cooperate in translation with the slide 445, this other portion of the other of the two branches of the U of the base 412 (upper branch ) has for example a notch to partially surround the slide 445 or a through opening forming a passage for the slide 445.

In order to exert a pressing force (arrow A) by the feeler head 423 on a portion of the internal (or external) face 54 (51) of the part which is oriented for example in the horizontal direction and allow the return to the rest position (FIG. 15A) of the support portion 414 relative to the base 412 along the vertical axis Z, two compression springs 446 and 447 are used forming means for returning the portion of support 412. These springs 446 and 447 are mounted on the rail 444 on either side of the upper branch of the support portion 414. These springs 446 and 448 have one end in contact and bearing on the support portion 414 and one end in contact and bearing on the base 412 (each spring bearing on a different branch of the base 412). These are for example, as in the example shown in FIGS. 15A and 15B, two helical springs 446 and 447. In the example shown in FIGS. 15A and 15B, these are two springs 446 and 447 of the same length and the same compressive strength per unit of length, which places the rest position (see Figure 15A) of the support portion 414 between the two arms (ends in the measuring direction Z) of the base 412.

However, the geometric and / or physical characteristics of each spring 446 and 447 can be adapted according to specific needs. It is understood that in this arrangement, the bearing force A of the probe head 423 on the part 50 depends on the deformation of the springs: thus in the case of FIG. 15B, the probe head 423 presses on the internal face 54 of part 50, in the area on the right in the figure, which has a re-entrant shoulder, on a portion of horizontal surface which is here as seen by the camera; in this case, we shifted translation upwards in direction Z the sensor 410 relative to the part 50, which moved the support portion 414 relative to the base 412 down the distance dZ1 (see FIG. 15B) and put in compression

(more) the second spring 447 located under the upper branch of the support portion 414. We find this offset dZ1 between the first reference element 430 secured to the support portion 414 and the second reference element 450 secured to the base 412

As shown diagrammatically in FIG. 16, a shooting device 160 used in the measurement system according to the invention, for example according to one of the embodiments shown in the figures and described above, comprises:

- a camera and a set of lenses making it possible to place the focal plane of this shooting device 160 on the part 50 and on the first reference element 130 (230, 330, 430) but also if necessary on the second element 150 (250, 350, 450). In order to improve the contrast of the image taken by the shooting device 160, in its field of view 162, a light source 164 in rear lighting is placed in an embodiment as shown in FIG. 16. relation to the object (or objects) observed by the shooting device 160. In this way, the object or objects present in the field of view 162 (of the camera) of the shooting device 160 is / are placed between the shooting device 160 and the light source 164. This backlighting gives an image such as that of fig 17A (for a portion of sphere which is for example the probe head) , with a gray or dark / light gradient between the room and the outside of the room. Processing this image makes it possible (FIGS. 17B to 17F) makes it possible to obtain an image after processing I which makes it possible to very precisely delimit the position of the outline of this or these objects visible by the shooting device 160 (FIG. 17F).

In the foregoing, a technique has been described in which the determination of the position of the first reference element 130 (and where appropriate the position of the second reference element 150) is carried out optically by the device. shooting 160. The present invention can also be applied to the determination of the position of the first reference element 130 (and if necessary the position of the second reference element 150) in another way, and in particular by contact between another type of sensor and the first reference element 130 and, where appropriate, the position of the second reference element 150). It should be noted that when the determination of the position of the first reference element 130 and, where appropriate, the position of the second reference element 150) is carried out optically, this makes it possible to be freed from further deformation of the rod 131 (151) of the first (second) reference element 130 (150) and therefore of an offset of the first (second) reference element 130 (150) which would modify the measurement.

We can note common points between all or part of these embodiments. In particular between the measurement system of the first embodiment 100 (with the sensor 110 or the variant with the sensor 110 'coupled with the second reference element 150), of the second embodiment 200 and of the third embodiment 300, said guidance system 140, 240, 340 is a flexible system at least in the direction Y. in the case of the measurement system of the fourth embodiment 400, said guidance system 440 is a flexible system at least in the direction Z.

Also, in particular between the measurement system of the first embodiment 100, the second embodiment 200, the third embodiment 300 and the fourth embodiment 400, one or the other or more of the provisions following A to J

applies for a sensor also subject of the present invention or for a measurement system object of the present invention and

comprising such a sensor:

* Arrangement A: the sensor forms a mechanical probing device able to be used for determining the internal profile of a part 50, comprising: - a base,

- a support portion connected elastically to the base by a guide system,

- a probe head mounted via a probe rod on the support portion,

- a reference head mounted via a reference rod on the support portion, in which:

the reference head and the probing head are located on the side of the support portion opposite to said base,

- The reference rod and the probing rod are arranged in a plane Y, Z being, in the rest position of the device, parallel to each other and to a direction Z.

* Layout B: said guide system is arranged so that when the probe head enters and remains in contact with a surface of the part, a relative movement between the probe head and the base is at least partially transmitted to the reference head via the guidance system.

* Layout C: said guide system is arranged so that when the probe head enters and remains in contact with a surface not parallel to the plane Y, Z, any relative displacement between the probe head and the base according to the direction Y is at least partially transmitted to the reference head via the guidance system.

* Arrangement D: said guide system comprises at least one spring element. In particular, the guide system comprises two spring blades parallel to each other and connecting said support portion to said base, the plane of each leaf spring being, in the rest position of the device, orthogonal to the direction Y.

* Arrangement E: the probe head is mounted at the free end of the probe rod and the reference head (first element

reference) is mounted at the free end of the reference rod. * Arrangement F: the feeler rod and the reference rod are of the same length

* Layout G: device further comprising a calibration indicator (second reference element) mounted integrally with the base and located near the reference head.

This calibration indicator (second reference element) makes it possible to detect the offset in Y (or in Z, or in X) of the probe head.

* Arrangement H: a measurement system includes such a mechanical probing device and an external device with an external sensor (such as for example a shooting device) capable of determining the position of the reference head (first reference element).

* Arrangement I: such a measurement system in which the external sensor is an optical device with an optical sensor, the optical axis of which is arranged orthogonal to the plane (Y, Z).

Arrangement J: the measurement direction is orthogonal to said main axis (Z) of the sensor (110), for example along the horizontal direction Y.

The first embodiment 100, the second embodiment 200, the third embodiment 300 and the fourth embodiment 400 of the measurement system as described above comprise a mechanical sensor, therefore are examples of a contact determination technology. However, the measurement system according to the present invention can also be presented as a contactless system.

Such a measurement system according to the present invention can equip a measurement bench, a workpiece control station during machining and can even be integrated as a module of a machine tool. Reference numbers used in the figures

X Transversal axis

Y Measuring axis

Z Main axis (vertical)

Y0 Distance from the probe to the first

reference element

ZO Distance between the probe head and the first reference element of the support portion

dY1 Offset between the base and the support portion in the measurement position

I0 Groove width 114c

LO Groove length 114c

F1 Arrow (movement of sensor 110)

F2 Arrow (movement of sensor 110)

F3 Boom (displacement of support portion relative to base 112)

A Arrow (bearing force of the first reference element 130 on the part 50)

R Reference line (vertical passing through the second reference element 150)

M Line for measuring the internal profile of the internal face 54

C Line following the internal profile to be measured

50 Piece

51 Face to be measured (external face)

52 Housing (hole, bore ...)

54 Face to be measured (internal face)

100 Measuring system (first embodiment)

110 Sensor

110 'Sensor

112 Base

112a First end

112b Second end

114 Support portion

114a First end of the support portion

114b Second end of the support portion 114c Groove

120 Probe

122 Probing rod

123 Probe head

130 First reference element

131 Rod of the first reference element

140 Guidance system

141 First leaf spring

142 Second leaf spring

143 Bar

143a First end of the bar

143b Second end of the bar

150 second reference element

151 Rod of the second reference element

160 Camera

162 Field of view of the Shooting device

164 Light source

I Image after treatment

200 Measuring system (second embodiment)

210 Sensor

212 Base

214 Support portion

220 Probe

222 Probing rod

223 Probe head

230 First reference element

231 Rod of the first reference element

240 Guidance system

241 Weight

250 second reference element

251 Rod of the second reference element

P Axis of rotation between 214 and 212

L1 Lever arm length

300 Measuring system (third embodiment)

310 Sensor Base (stirrup-shaped)

Support portion (L-shaped sliding sliding carriage) Probe

Probe rod

Probe head

First reference element

First reference element rod

Guidance system

Rail

Slide

First coil spring

Second coil spring

second benchmark

Second reference element rod

Measuring system (third embodiment)

Sensor

Base (stirrup-shaped)

Support portion (U-shaped sliding sliding carriage) Probe

Probe rod

Probe head

First reference element

First reference element rod

Guidance system

Rail

Slide

First coil spring

Second coil spring

second benchmark

Second reference element rod

Claims

1. Measuring system (100; 200; 300; 400) of an external profile of a part (50) or of an internal profile of a hollow part (50), comprising:

- a part (50) whose internal or external profile is to be measured,

- a sensor (110, 110 '; 210; 310; 410) comprising a probe (120; 220; 320;

420), a first reference element (130; 230; 330; 430) integral with the probe (120; 220; 320; 420), a base (112; 212; 312; 412) and a guidance system (140; 240; 340; 440) connecting the probe (120; 220; 320; 420) with the base (112; 212; 312; 412) allowing relative movement between them according to at least one degree of freedom defining a measurement direction,

- said sensor (110, 110 '; 210; 310; 410) being arranged so that when the sensor is displaced relative to the workpiece in a direction different from the direction of measurement, said probe (120; 220; 320; 420 ) is able to follow the internal or external contour of the part (50) while the first reference element (130; 230; 330; 430) is outside the part (50) and performs a path reproducing the path the probe (120; 220; 320; 420) along the internal or external contour of the part (50), and

- a shooting device (160) capable of taking images representing at least a portion of the outside of the part (50) and the first reference element (130; 230; 330; 430), whereby by comparison between the images taken by the shooting device (160), the

relative displacement between the first reference element (130; 230; 330; 430) and the portion of the outside of the part (50) in said measurement direction, and a relative displacement is deduced therefrom between the probe (120; 220 ; 320; 420) and the base (112; 212; 312; 412) which corresponds to an offset in the measurement direction along the measured profile of the part (50).

2. Measuring system (100; 200; 300; 400) according to claim 1, in which the internal contour or the external contour of the part (50) forms a face of revolution about an axis.

3. Measuring system (100; 200; 300; 400) according to claim 2, wherein said guide system (140; 240; 340; 440) allows a single degree of freedom between the probe (120; 220; 320; 420) and the base (112; 212; 312; 412).

4. Measuring system (100; 200; 300; 400) according to claim 2 or 3, further comprising a second reference element (150; 250; 350; 450) integral with the base (112; 212; 312; 412 ) and arranged outside the room (50), said second reference element (150; 250; 350; 450) being placed so that the camera (160) is capable of simultaneously seeing said first element reference (130; 230; 330; 430), said second reference element (150; 250; 350; 450) and said portion of the outside of the part (50).

5. Measuring system (100; 200; 300; 400) according to any one of claims 1 to 4, in which

the probe (120; 220; 320; 420) comprises a probing head (123) able to follow and detect the internal or external contour of the part (50) by contact.

6. Measuring system (100; 200; 300; 400) according to any one of claims 1 to 4, in which

the probe (120; 220; 320; 420) comprises a detection head capable of tracking and detecting the internal or external contour of the part (50) without contact.

7. Measuring system (100; 200; 300; 400) according to any one of claims 1 to 6, in which

the shooting device (160) comprises a camera and a light source (164) capable of simultaneously illuminating said portion from the outside of the room (50) and the first reference element (130; 230; 330; 430) .

8. Measuring system (100; 200; 300; 400) according to claim 7, in which

the camera has a field of view (162) making it possible to see said portion from the outside of the part (50) and the first reference element (130; 230; 330; 430).

9. Measuring system (100; 200; 300; 400) according to any one of claims 2 to 8, in which

the guidance system (140; 240; 340; 440) includes return means allowing the return of the probe (120; 220; 320; 420) in a rest position relative to the base (112; 212; 312; 412) when the probe (120; 220; 320; 420) is no longer interacting with the internal or external contour of the part (50).

10. Measuring system (100; 200; 300; 400) according to any one of claims 1 to 9, in which

the guide system (140; 240; 340; 440) comprises between the probe (120; 220; 320; 420) and the base (112; 212; 312; 412) a sliding connection or else a tilting connection.

11. Measuring system (200) according to any one of claims 1 to 9, in which:

the part (50) is hollow and the internal contour of the part (50) forms a face (54) of revolution around an axis of revolution,

- the probe (220) comprises a probing head (223) able to detect by contact the internal contour of the part (50) and to follow the internal contour of the part (50) with a degree of freedom in a direction (Y) of measurement perpendicular to said axis of revolution, this direction (Y) of measurement separating between them the probe head (223) and the first reference element (230),

the guidance system (240) comprises a tilting connection between the probe (120; 220; 320; 420) and the base (112; 212; 312; 412) around an axis (P) perpendicular to said axis of revolution and orthogonal to the direction (Y) of measurement.

12. Measuring system (200) according to the preceding claim, further comprising a second reference element (250) integral with the base (212) and located outside the room, the shooting device (160) being able to take an image further comprising the second reference element (250), whereby the variation of the relative position between the first reference element (230) and the second reference element (250) allows the measurement of the profile of the internal contour of the part (50).

13. Method for measuring an internal profile of a hollow part (50), comprising the following steps:

i) supply of a sensor (110, 110 '; 210; 310; 410) comprising a probe (120; 220; 320; 420), a first reference element (130; 230; 330; 430) integral with the probe (120; 220; 320; 420), a base (112; 212; 312; 412) and a guidance system (140; 240; 340; 440) connecting the probe (120; 220; 320; 420) with the base (112; 212; 312; 412) by allowing relative movement between them according to at least one degree of freedom defining a direction of measurement, and provision of a shooting device (160),

ii) supply of a hollow part (50) whose internal profile is to be determined,

iii) placing the sensor (110, 110 '; 210; 310; 410) so that the probe (120; 220; 320; 420) is inside the part (50) and detects a point in the internal profile of the part (50) while the first reference element (130; 230; 330; 430) is outside the part (50) and in the field of view of the shooting device (160),

iv) triggering of the shooting system and formation of an image representing at least a portion of the outside of the part (50) and said reference element,

v) displacement of the sensor (110, 110 '; 210; 310; 410) relative to the part (50) according to a movement in a direction different from the direction of measurement and allowing the probe (120; 220; 320; 420 ) stay inside the part and follow the internal contour of the part (50), while the first reference element (130; 230; 330; 430) remains outside the part (50) by performing the same movement as the probe (120; 220; 320; 420),

vi) carry out steps iv) and v) for other points of the internal contour of the part (50).

14. Method for measuring an external profile of a part (50), comprising the following steps:

i) supply of a sensor (110, 110 ';210;310; 410) comprising a probe (120; 220; 320; 420), a first reference element (130; 230; 330; 430) integral with the probe (120; 220; 320; 420), a base (112; 212; 312; 412) and a guidance system (140; 240; 340; 440) connecting the probe (120; 220; 320; 420) with the base (112; 212; 312; 412) allowing relative movement between them according to at least one degree of freedom defining a direction of measurement, and providing a camera (160),

ii) supply of a part (50) for which it is desired to determine the external profile,

iii) placing the sensor (110, 110 '; 210; 310; 410) so that the probe (120; 220; 320; 420) is outside the part (50) and detects a point on the external profile of the part (50) while the first reference element (130; 230; 330; 430) is also outside the part (50) and in the field of view of the shooting device (160),

v) displacement of the sensor (110, 110 '; 210; 310; 410) relative to the part (50) in a movement in a direction different from the measurement direction and allowing the probe (120; 220; 320; 420 ) follow the external contour of the part (50), while the first reference element (130; 230; 330; 430) remains outside the part (50) by performing the same movement as the probe (120; 220 ; 320; 420),

vi) carry out steps iv) and v) for other points of the external contour of the part (50).

15. Method for measuring a profile of a part (50), comprising the following steps:

ii) supply of a part (50) whose profile is to be determined, iii) placing the sensor (110, 110 ';210;310; 410) so that the probe (120; 220; 320; 420) detects a point on the contour of the part (50) while the first reference element ( 130; 230; 330; 430) is outside the room (50) and in the field of view of the shooting device (160), iv) triggering of the shooting system and formation of an image representing at least a portion of the outside of the part (50) and said reference element,

v) displacement of the sensor (110, 110 '; 210; 310; 410) relative to the part (50) in a movement in a direction different from the measurement direction and allowing the probe (120; 220; 320; 420 ) follow the contour of the part (50), while the first reference element (130; 230; 330; 430) remains outside the part (50) by performing the same movement as the probe (120; 220; 320; 420),

vi) carry out steps iv) and v) for other points of the contour of the part (50).

16. Measuring method according to one of claims 13 to 15 in which the following steps are also carried out:

a) for each image formed by said shooting device (160), calculation of the relative position between the first reference element (130; 230; 330; 430) and the portion of the outside of the part (50) , and

b) reconstruction of the measured profile of the part (50) from said relative positions of the first reference element (130; 230; 330; 430)

successively calculated.

17. Measuring method according to one of claims 13 to 16 in which the following steps are also carried out:

- the images taken by the shooting device (160) are compared in order to detect the relative displacement between the first reference element (130; 230; 330; 430) and the portion of the outside of the part (50) in said measurement direction, and

- a relative displacement is deduced therefrom between the probe (120; 220; 320; 420) and the base (112; 212; 312; 412) which corresponds to a shift in the direction of measurement along the measured profile of the part ( 50).

18. The measurement method as claimed in claim 14, in which the part (50) is hollow and the internal contour of the part (50) forms a face (54) of revolution around an axis of revolution,

19. The measurement method according to claim 18, in which the sensor (110, 110 '; 210; 310; 410) further comprises a second reference element (250) integral with the base (212) and located outside. of the part (50), the shooting device (160) being able to take an image further comprising the second reference element (250), whereby the variation of the relative position between the first reference element ( 230) and the second reference element (250) allows the measurement of the profile of the internal contour of the part (50).